How to add a custom iptables rule from the command line

With ASL, you can also add iptables rule from the command line, and ASL will remember it automatically.

Remember to watch the order of your rules. For example, if you add an INPUT rule with append, and ASL is managing what ports are allowed to connect, that rule will never trigger as the final ASL rule (again if youre using ASL to manage inbound ports) is a DROP and LOG rule.